Breaking or excavating tool with cemented tungsten carbide insert and ring

1. A breaking or excavating tool, comprising:

a body having a mounting end and a working end;

a seating surface at the working end including a cavity and axially projecting sidewalls formed integral to the body, the sidewalls having an axially forwardmost surface oriented perpendicular to an axis of the tool adjoining a radially outermost surface oriented parallel to the axis of the tool;

an insert mounted within the cavity having a tip at an axially forwardmost end, a tapered forward surface, a side surface and a transition edge at an intersection of the forward surface and the side surface; and

a ring located radially outward of the projecting sidewalls, the ring formed of a material harder than the body of the tool,

wherein the transition edge and an axially forwardmost surface of each of the sidewalls and the ring are arranged in an axially rearwardly extending stepped configuration;

wherein the axially forwardmost surface of the ring is at an axial distance D from the tip of the insert and an axially rearwardmost surface of the ring is at an axial distance d from the tip of the insert; and

wherein in the interval D to d, the ring is the radially outermost portion of the tool.

2. The tool according to claim 1 , wherein an axially rearwardmost surface of the insert is at an axial distance L from the tip of the insert, and wherein 0.5L≦D≦0:9L.

3. The tool according to claim 2 , wherein 0.5L≦D≦0.8L.

4. The tool according to claim 2 , wherein d is greater than D and d is less than L.

5. The tool according to claim 4 , wherein 0.5L≦D≦0.8L and wherein d≦0.9L.

6. The tool according to claim 1 , wherein a radial thickness of the sidewalls is maximally l s , wherein a radial thickness of the ring is maximally l r , and, wherein l r is greater than or equal to l s .

7. The tool according to claim 6 , wherein 1 mm≦l s ≦1 mm.

8. The tool according to claim 1 , wherein the transition edge and a radially outermost portion of the axially forwardmost surface of each of the sidewalls and the ring are arranged on a ballistic envelop of the tool.

9. The tool according to claim 8 , wherein the ballistic envelop forms an angle of about 60 degrees or less.

10. The tool according to claim 1 , wherein the insert is mounted in the cavity with a full braze.

11. A material removal machine, comprising:

a rotatable member; and

one or more breaking or excavating tools mounted on the rotatable member,

wherein the breaking or excavating tool, includes:

a body having a mounting end and a working end,

a seating surface at the working end including a cavity and axially projecting sidewalls formed integral to the body, the sidewalls having an axially forwardmost surface oriented perpendicular to an axis of the tool adjoining a radially outermost surface oriented parallel to the axis of the tool,

an insert mounted within the cavity having a tip at an axially forwardmost end, a tapered forward surface, a side surface and a transition edge at an intersection of the forward surface and the side surface, and

a ring located radially outward of the projecting sidewalls, the ring formed of a material harder than the body of the tool,

wherein the transition edge and an axially forwardmost surface of each of the sidewalls and the ring are arranged in an axially rearwardly extending stepped configuration;

wherein the axially forwardmost surface of the ring is at an axial distance D from the tip of the insert and an axially rearwardmost surface of the ring is at an axial distance d from the tip of the insert; and

wherein in the interval D to d, the ring is the radially outermost portion of the tool.

12. The material removal machine according to claim 11 , wherein an axially rearwardmost surface of the insert is at an axial distance L from the tip of the insert, and wherein 0.5L≦D≦0.9L.

13. The material removal machine according to claim 12 , wherein d is greater than D and d is less than L.

14. The material removal machine according to claim 11 , wherein the transition edge and a radially outermost portion of the axially forwardmost surface of each of the sidewalls and the ring are arranged on a ballistic envelop of the tool.

15. The material removal machine according to claim 14 , wherein the ballistic envelop forms an angle of about 60 degrees or less.

16. The material removal machine according to claim 11 , wherein the material removal machine is an underground mining machine, a surface mining machine, a road planning machine, a trencher or a reclaiming machine.

17. A method of manufacturing a breaking or excavating tool, the method comprising:

forming a first seating surface at a working end of a body of the tool, the seating surface including a cavity and axially projecting sidewalls formed integral to the body, the sidewalls having an axially forwardmost surface oriented perpendicular to an axis of the tool adjoining a radially outermost surface oriented parallel to the axis of the tool;

forming a second seating surface radially outward of the cavity of the first seating surface;

mounting an insert to the first seating surface, the insert including a tip at an axially forwardmost end, a tapered forward surface, a side surface and a transition edge at an intersection of the forward surface and the side surface; and

mounting a ring to the second seating surface, wherein the mounted ring is located radially outward of the projecting sidewalls and wherein the ring is formed of a material harder than the body of the tool,

wherein the transition edge and an axially forwardmost surface of each of the sidewalls and the ring are arranged in an axially rearwardly extending stepped configuration;

wherein the axially forwardmost surface of the ring is at an axial distance D from the tip of the insert and an axially rearwardmost surface of the ring is at an axial distance d from the tip of the insert; and

wherein in the interval D to d, the ring is the radially outermost portion of the tool.

18. The method according to claim 17 , wherein at least one of mounting the insert and mounting the ring includes a full braze.

19. The method according to claim 17 , wherein an axially rearwardmost surface of the insert is at an axial distance L from the tip of the insert, and wherein 0.5L≦D≦0.9L.

20. The method according to claim 19 , Wherein d is greater than D and d is less than L.

21. The method according to claim 17 , wherein the transition edge and a radially outermost portion of the axially forwardmost surface of each of the sidewalls and the ring are arranged on a ballistic envelop of the tool.

22. The method according to claim 21 , wherein the ballistic envelop forms an angle of about 60 degrees or less.

23. A breaking or excavating tool, comprising:

a body having a mounting end and a working end;

a seating surface at the working end including a cavity and axially projecting sidewalls formed integral to the body;

an insert mounted within the cavity having a tip at an axially forwardmost end, a tapered forward surface, a side surface and a transition edge at an intersection of the forward surface and the side surface; and

a ring located radially outward of the projecting sidewalls; the ring formed of a material harder than the body of the tool,

wherein the transition edge and an axially forwardmost surface of each of the sidewalls and the ring are arranged in an axially rearwardly extending stepped configuration;

wherein an axially rearwardmost surface of the insert is at an axial distance L from the tip of the insert, wherein an axially rearwardmost surface of the ring is at an axial distance d from the tip of the insert, and wherein d is less than L; and

wherein in the interval D to d, the ring is the radially outermost portion of the tool.